PLAINS, Georgia (AP) -- The mayor of former President Jimmy Carter's hometown said Monday that the city acted immediately to remove an effigy of President Barack Obama that was found hanging from a building. Mayor L.E. Godwin III said he was shocked when the large black doll was found Saturday morning on Main Street in the small Georgia town. U.S. Secret Service spokesman Ed Donovan says the agency is investigating. He declined to elaborate. Footage from WALB-TV showed the doll hanging by a noose in front of an official sign that says "Plains, Georgia. Home of Jimmy Carter, our 39th President." A witness told the television station that the doll wore a sign with Obama's name on it. Godwin says he couldn't read the sign on the doll because it was curled up. Carter is a Democrat, as is Obama, the country's first black president. Last year Carter criticized a Republican senator who heckled Obama during a health care speech to Congress, saying he felt the outburst was based on racism. "There is an inherent feeling among many in this country that an African-American should not be president," Carter said in September. The use of a noose for the effigy evokes powerful racial symbolism. The U.S. South has a painful history of racial lynchings, in which white mobs hanged blacks.